1912 HD Belt Twin (AKA EVIL TWIN)

[rwm]

Turn coat amongst us

stop the okuma and bar the door. anybody hear that big groan for oely this weekend? the redheaded step child (the evil twin) sat home while joe paraded around on his new canon ball ride. say it aint so joe.

[Slojo]

No Trade

IT AINT SO Robby. Busted again (on the Pat Murphy Henderson) this time mixing with the enemy Mark Hill and the always pesky Wolfe Pack. It appears Mark has dedicated his life to developing an abundance of Detroit built Hendersons and those other brand X fours from Chi. Town in an attempt to prove their capable of keeping up with a certain little silent gray fellow by targeting my back. Good thing because that is where I would like to keep them.

Oley was another fine example that good parts are still waiting to be purchase for those all important projects. To bad flat tank Harley parts were slim to almost none and heavily priced. I did find a few trinkets, its always a good meet when you don't leave empty handed.

joe

[c.o.]

It just doesn't look like you felt at home on it Joe...

[Slojo]

Cory

How observant , actually the seat suspension had fallen apart and required some attention. Pat brought the Henderson for its first meet and it experienced a seat failure.

joe

[Slojo]

Mushroom Season

While near completion of developing a new part program for the next hub part a wild lightning storm rolled in, juice everywhere. I don't take chances with my equipment in electrical storms so the best thing is to shut down for the evening. One good blast could cost way to much.

An order placed today for a Big Twin crank pin, Sportster big end rod races, rollers and cages . The crank pin over all length will get cut to a new length , new tapers ground and rethreaded to suite my application. Using a finished crank pin saves heat treat and finishing of the O.D. This is the same procedure used on the Ghost.

joe

[c.o.]

Cory

How observant , actually the seat suspension had fallen apart and required some attention. Pat brought the Henderson for its first meet and it experienced a seat failure.

joe

So you're saying the experience was a pain in the a$$? Nice strategy with "keeping the enemy close".

I like a good lightning storm. That is, if it's followed by heavy rain. Forest fires suck. So would major machine equipment failure! You need some sort of steam powered, belt driven type backup!

[Slojo]

Coaster, on the Skids

Temporarily side tracked from the coaster project and redirected to cylinders and connecting rods.

The cylinders are a matched set by serial numbers and are original 1912 only cylinders. I acquired this set of cylinders not as a set but individually with several years between the acquisition . These cylinders are with standard bore and near perfect condition . The only flaw is a couple damaged fins and one cylinder is with a wrist pin grove worn in its bore. To get one of the cylinders I had to convince Danny (he loaned his 1914 twin during the Ghost build for reference) to extract the 1914 twin motor form his running bike, remove the 1912 cylinder and trade it for a 1914 cylinder (supplied by yours truly) to correct both of our bikes. Coming up with a 1914 cylinder was no easy task but accomplished !

After months of deliberation on cylinder repair a decision was made to TIG weld the wrist pin damage with silicon bronze. The damaged 1912 cylinder was sent out for repairing the wayward wrist pin damage. Process, preheat the cylinder to 500 degrees and run the weld, reheat and the burry it in floor dry for a slow cool down process. No pinging or cracks !

I can now cut the cylinders and get a finish bore size for ordering pistons.

Three days of machining and the connecting rods are near finished. Reused the scrap female rod (invert the Y axis, remember?) from the Ghost project to make a male rod for this Twin. Rod races , donor crank pin blank and bearings are on order and will halt the rod project just in time to get back on the cylinder and coaster processes.

[Slojo]

Why does the edit function no longer work?

[fillibuster]

Why does the edit function no longer work?

"Why does the edit function no longer work?" ..... edit/copy/paste off the top tool-bar? ... no? .... not what you meant.....

[rwm]

Why does the edit function no longer work?

they national voted to move it to buzz's forum

[Slojo]

Trouble in Paradise

After posting an article in the hazy evening hours a reread will turn up a misspell or grammar error. In the past this could be easily rectified within a day or so, now it is locked in. An edit function is displayed and editing is possible in the temporary file it just won't transfer to the permanent file that we all read from. HELP!

joe

[Slojo]

"edit post" and "save" function aredisplayed and editing is possible in the temporary file it just won't transfer to the permanent file that we all read from. HELP!

[Slojo]

Key Number Yesterday 80

The Monarch lathe was perspiring heavily yesterday and it wasn't even working hard. To much great weather to soon permitted into the shop , everything including the floor is wet and slippery from condensation. De-Humidifier season in Michigan is much better than heater season.

Five days into the connecting rod project, the rods are ready for steel shot penning .
Today the cylinders will be bored for clean up size validation in order to know what size pistons will be required. An order will be placed with CP pistons again as I know what to expect from their pistons as relates to clearances and durability.

Photos to follow if Cory is awake up their in the mountain country. Time is running down, an hour and a half has gone into preparing this article and photo down loading this morning. Finding and sorting photos after downloading is the greatest time waste. Brevity may be the key from now on.

joe

[Slojo]

It appears Cory's email address has failed on the receiving end.
joe

[Slojo]

Cylinders

While preparing for knucklehead action , organizing the many parts required to build a set of heads I also made tooling, a set up, and converted a boring program into an ID grinding program for processing the welded front cylinder on the Okuma . Okuma Jig Grinder???

An arbor made from hardened and ground piece of scrap tooling salvaged from the dumpster worked perfectly for mounting the grinding wheel. Next a fixture mounting plate to hold the cylinder in the machining center was made from an Okuma motor mount plate. Just proves old Okumas never die they just get re"cycled" , into motorcycle tools.

Excess weld material in the front cylinder was machined off using carbide tooling, lots of carbide tooling. The metallurgic make up of the cast iron combined with the silicon bronze (and possible tungsten from the TIG torch) caused carbide eating hard or abrasive spots while machining. Once close to size , grinding became the obvious answer to the problem.

Fellow Cannonballer Chris Price will finish hone these cylinders , damage to his honing tools will result if the weld is not cleaned up smooth with the bore. In this front cylinder the piston must have been reciprocating sideways with a twisted bent connecting rod for some time prior to the wrist pin destruction.

Front cylinder bore measured 3.307 at the bottom of the stroke where the least amount of wear takes place. An unusual wear pattern required excess valuable material to be ground out of the cylinder bore. End result, finish bore size grew to 3.334" nearly .030" over bore. The rear cylinder may get a smaller piston if it cleans up early in the process.


On to the next problem, the finished cylinder had an issue where the bore meets the open combustion chamber . Either casting shift or qualifying of the cylinder during OEM manufacturing caused for the bore to terminate into a shoulder where their should be an opening larger than the bore.

Blind hole cylinders are difficult for this reason alone. A 5/8" carbide burr and a six inch extension mounted in a slow spinning drill motor made quick work of the problem easily cutting away minimal material for hone clearance.

joe